In general, a submarine with passengers or loads loaded therein is conventionally used as a vehicle cruising in the water such as sea or lake, and, in recent years, such submarine has been utilized as leisure submarine used for viewing the sight in the water or the like.
However, the above submarine suffers a problem that it is impossible to operate it in a stormy weather, resulting in a disadvantage arisen in many cases, and it is impossible to give a sightseer satisfaction.